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When to plant Zinnia in Pine County, MN

Plant Zinnia in Pine County during the brief May 24–June 14 window. With 142 frost-free days, fall plantings can't mature before September 29.

When to Plant Zinnia in Pine County, MN

Zinnia (Zinnia elegans) is a fast-growing, heat-loving annual that produces bold, dahlia-like blooms from early summer until hard frost. One of the easiest flowers to grow from direct-sown seed, zinnias thrive in hot, dry conditions and are magnets for butterflies and beneficial insects. They make excellent companion plants alongside marigolds in the vegetable garden.

Pine County, Minnesota is in USDA Zone 4a. The average last spring frost is May 10 and the first fall frost is September 29, giving you a growing season of approximately 142 days.

At an elevation of 538 feet, Pine County receives approximately 33.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Zinnia to ensure they mature before fall.

Annual Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Pine County, MN (Zone 4a) Short season
142 days
Last Spring Frost May 10
142 growing days
First Fall Frost September 29

Pine County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.3

Drainage

Well Drained

Monthly Watering Guide for Zinnia

Zinnia needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Zinnia Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 3.3" 0" ❄️ Dormant
May 4.3" 3.6" 0.7" 💧 Light watering
Jun 4.3" 4.4" 0" ✅ Rainfall sufficient
Jul 4.3" 3.8" 0.5" 💧 Light watering
Aug 4.3" 3.1" 1.2" 💧 Light watering
Sep 4.3" 3.5" 0.8" 💧 Light watering
Oct 2.3" 0" ❄️ Dormant
Nov 2.1" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Pine County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Zinnia Planting Timeline — Pine County, MN

Zinnia Planting Calendar

Activity When Date Range
Start Indoors April 12 Apr 12 – Apr 26
Transplant Outdoors May 24 May 24 – Jun 7
Direct Sow May 24 May 24 – Jun 14
Bloom August 2 Aug 2 – Oct 11

Plant 0.3" deep · 12" apart · Rows 18" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
July
August Bloom
September Bloom
October Bloom
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

60–70 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 4a

📆 Growing Season

142 days in Pine County

Growing Tips for Pine County

Direct-sow after last frost when soil reaches 60°F; seeds germinate in 5-7 days. In zones 3-5 a brief indoor start (4 weeks) is worthwhile but transplant carefully — zinnias dislike root disturbance. Deadhead frequently to extend bloom. Excellent cut flower; harvesting regularly encourages branching. Avoid overhead watering to reduce powdery mildew.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Zinnia in Pine County, MN?

Pine County is in Zone 4a with an average last frost of May 10. Plan your Zinnia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Pine County, MN?

Pine County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 10 and first fall frost is September 29.

When should I plant Zinnia in Pine County, MN?

In Pine County, MN, plant Zinnia after the last frost (around May 10) and before the first frost (around September 29). Best results when soil holds above 50°F.

What growing zone is Pine County, MN for Zinnia?

Pine County sits in USDA Zone 4a. Zinnia grows reliably in zones 3a through 11b, so it's a good fit here.

Can Zinnia grow in Pine County's climate?

Yes — Zinnia grows well in Pine County's temperate climate. Pine County averages a 142-day frost-free season, with last frost around May 10 and first frost around September 29.

🌱

Your Pine County Garden Planner — Free

A 22-page printable planner built for Pine County (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Pine County, MN. Local conditions may vary. Last updated: July 2026.

Sources & credits

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